McDonnell told Peston: “Well I think better we have a general election. Better we have a general election. On the issue, and all the other issues, because you then have a wider debate as well.”

Corbyn told Peston last month: “We are not supporting or calling for a second referendum. What we have called for is a meaningful vote in Parliament.”

When it was put to Corbyn that he was not saying he would never support another referendum, the Labour leader said: “We are not calling for one either”.

Asked about a second referendum on any Brexit deal, shadow foreign secretary Emily Thornberry told BBC1′s Andrew Marr Show last month: “If 90% of the population was now saying we must stay in the European Union and we must not leave then that would be a challenge that would be there for all of us who are democrats.

“But, at the moment, and as things currently stand, we proceed in good faith, we do as we are instructed and we are leaving the European Union.

“We have said that we must respect the result of the referendum which means that we have to leave, but we have to look after the economy which, in my view, means that we don’t go very far.”